Banished Saint Helena Awl Snail (Chilonopsis exulatus)  

This species, like all members of the genus, comes from the island of Saint Helena, it was described in the year 1852 based on subfossil shells.  

The shells reached a height of ca. 2 cm.  

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The species seems to have survived quite long, maybe even until the beginning of the 19th century, Thomas Vernon Wollaston writes hereto in the year 1878 (Testacea Atlantica).:  

“My own belief however is that in all probability it was as much subfossilized as are the bleached and still coloured examples of the B. helena, Quoy, which lie scattered loosely in many places on the summit of the Barn; and until further evidence therefore has been adduced, I suspect that it will be safer to treat it as belonging to the extinct fauna of the island, though with the appearance of its having lingeredon (like the B. helena) into comparatively recent times.” [1]  

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References:  

[1] T. Vernon Wollaston: Testacea Atlantica: or the Land and Freshwater Shells of the Azores, Madeiras, Salvages, Canaries, Cape Verdes, and Saint Helena. London: L. Reeve & Co. 1878  

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edited: 21.03.2018